Nut-tapping machine.



F. C. HOFFMAN.

NUT TAPPING MACHINE.

APPLICATION FILED AUG.15, 1912.

1,1 1 1,833, Patented Sept. 29, 1914.

5 SHEET8SHEET 1.

W WZ% j M BY A TTORNEY P. 0. HOFFMAN.

NUT TAPPING MACHINE.

APPLICATION FILED AUG. 15, 1912.

1,1 1 1,833. Patented Sept. 29, 1914.

5 BHEETBSHBET 21 WITNESSES: mmvmn Jzd m BY ,4 TTOHNEY F. C. HOFFMAN.

NUT TAPPING MACHINE.

APPLICATION FILED AUG.15,1912.

5 SHEETSSHBET 3.

Patented Sept. 29, 1914.

INVENTOR W 6 W WITNESSES.

ATTORNEY F. C. HQFFMAN. NUT TAPPING MACHINE.

APPLICATION FILED AUG.15', 1912.

1,1 1 1,833. Patented Sept. 29, 1914.

5 SHEETS8HEET 4.

\ j 68 v I e 9 WITNE88E8: IN l/E IV TOR imam.

A TTORNEY F. C. HOFFMAN.

NUT TAPPINGMAOHINE. APPLICATION FILED AUG.15, 1912.

1,1 1 1,833, Patented Sept. 29, 1914.

5 SHEBTS-$HEET 5.

I WITNESSES: INVENTOR .m By 5 W A TTOR/VEY UNITED STATES PATENT OFFICE.

FREDERICK C. HOFFMAN, OF THOMASTON, CONNECTICUT, ASSIGNOR TO THE BLAKE AND JOHNSON COMPANY, OF WATERBURY, CONNECTICUT, A CORPORATION OF CON- NECTICUT.

NUT-TAPPING MACHINE.

Specification of Letters Patent.

Patented Sept. 29, 1914.

To all whom it may concern:

Be it known that I, FREDERICK C. Horr- MAN, a citizen of the United States, residing at T homast-on, county of Litchfield. State of Connecticut, have invented an Improvement in Nut-Tapping Machines, of which the following is a specification.

This invention has for its object to provide a simple, inexpensive, easily operated, durable and quick-acting automatic machine for tapping nuts. With this object in view I have devised the novel machine of which the following description in connection with the accompanying drawings is a specification, reference characters being used to indicate the several parts.

Figure 1 is a front elevation of the machine complete; Fig. 2 a side elevation partly in section as seen from the right in Fig. 1; Fig. 3 a side elevation as seen from the left in Fig. 1; Fig. 4 a plan view of the hopper detached; Fig. 5 a perspective view of the agitator detached; Fig. 6 an elevation of the agitator driving wheel detached; Fig.

-' 7 a side elevation of the hopper and swinging carrier detached; Fig. 8 a similar view showing a changed position of the parts; Fig. 9 an elevation of the swinging carrier I as seen from the left in Fig. 7; Fig. 10 a plan view of the swinging carrier as seen in Fig. 7 the arms being in section; Fig. 11 an elevation of the swinging carrier detached and partly in section to show the retaining slide. the position corresponding with Fig. 8: Fig. 12 a perspective view of the retain ing slide detached; Fig. 13 a plan view of the upper jaws and closing wheel detached; F ig. 14 a side elevation of the closing wheel detached; Fig. 15 a perspective view on an enlarged scale of one of the jaws detached; 1

Fig. 16 a view of the shank of the tap detached, and Fig. 17 is a plan view of the rotating carrier detached.

20 denotes the framework, which may be of any ordinarv or preferred construction. Power is applied to drive the mechanisms bv means of belts (not shown) passing over a pulley 21 on a shaft 252 and a pulley 23 on a shaft 24. Shaft 22 carries a pinion 25 which meshes with a gear wheel 26 on a shaft 27 which also carries a cam 28 and a jaw clos- Shaft 24 carries a belt pul- 1 ing wheel 29. ley 30 from which a belt (see dotted lines in Fig. 1) extends over a belt pulley 31 on a i shaft 32 which carries a wheel 33 having pivoted thereto a block 34 which operates the agitator, as will presently be fully del scribed. l The blanks to be operated upon, indicated l by 84, and each having a central hole punched therein are thrown loosely into a l hopper 35. This hopper may be of any ordinary or preferred construction. The essential features are an inclined bottom 36, just back of the top of the inclined bottom a 5 chute 37 and back of the chute and extending upward therefrom a concave wall 38. 1 The side walls of the hopper incline toward Zthe bottom leaving the bottom just. wide enough to receive a blank freely when its sides are parallel with the sides of the hopper. In the front wall of the hopper is an inverted T-slot 39 in which the agitator re ciprocates. The agitator comprises a bottom plate 40 which sl des freely over the bottom, a central fin 41 projecting upward therefrom and a box 42 secured to the plate 5 at right angles thereto. The outer end of the agitator is supported by a bracket 43 se cured to the hopper and provided at its outer end with a slot through which the plate passes. The agitator is reciprocated by means of a block 34 which is pivoted to wheel 33 and slides in the box. as will be readily understood from Fig. 2 in connection with Figs. 5 and 6. In Fig. 2 the agitator is shown at the extreme of its outward movement. The plate is preferably the same thickness as the blanks and the fin is cut back from the front end of the plate leaving an incline terminating in a vertical wall 44. When the agitator is forced forward the blanks resting against the inclined bottom of the hopper, which can only lie with their sides parallel with the side walls g of the hopper, are forced forward by the plate and move up the inclined bottom past the mouth of the chute and up concave wall 38, the effect of which is to cause some of the blanks to ride up the curve and drop over backward on top of the supply in the hopper, while others will drop into the chute. as clearly shown. In practice the chute always 1 keeps full. The effect of the incline and vertical wall of the fin is to agitate the supply of blanks above the bottom layer and render packing or wedging practically impossible.

As the blanks drop out from the chute they are received singly in an arc-shaped swinging carrier 45 which is pivoted between arms 46 extending downward from the hopper. The swinging carrier is oscillated by means of cam 28 acting upon a roll 47 on an arm 48 pivoted to a bracket 49 and connected by means of a link 50 with an arm 51 which extends from a shaft 52 by which the swinging carrier is carried.

The roll is retained in engagement with the cam by means of a spring 64, one end of which is connected to arm 48 and the other to the framework. It will be obvious that each rotation of shaft 27 and the cam will swing the carrier from the position shown in Figs. 2 and 7 to the position shown in Figs. 8 and 11 and back again to the position in Figs. 2 and 7 hen the swinging carrier is in the position shown in Figs. 2 and 7 a blank slides from the chute into a socket 53 in the carrier which just receives it. The blank is retained in the socket while the carrier is swinging from the position in Fig. 7 to that in Fig. 8. by means of a slide 54 shown as provided with flanges overlying the edges of the carrier and retained in place thereon by a screw 55 passing through a slot in the slide and engaging the carrier. At the forward end of the slide is a recess 56 to prevent interference with the tap which is in dicated by 57. Vhen the carrier reaches the position shown in Fig. 8 the slide will have been entirely retracted, which permits the blank to pass from the carrier onto the tap, as will be more fully explained. The reciprocation of the slide is effected by means of an arm 58 pivoted to the carrier as at 59, the other end of which is pivotally connected to the slide. Near the end of the movement of the carrier from the position in Fig. 7 to that in Fig. 8, arm 58 will engage a bracket 60 which projects from one of the arms 46 and as the carrier reaches the end of its movement the arm will be forced backward by the bracket and will move the slide from the position in Fig. 7 to that in Fig. 8, releasing the blank and depositing it upon the cap. Near the end of the move ment of the carrier from the position in Fig. 8 to that in Fig. '7, arm 58 will engage a pin 61 projecting from one of the arms 46 and will be raised thereby and will raise the slide to the position in Fig. 7 ready to receive a blank from the chute and retain it in the socket. I t will be noted that the outer edge of the swinging carrier is an arc of a circle of which the pivotal point of the carrier is the center. This insures that the blanks will be retained in the chute by the carrier until the carrier is in position to receive a blank when one will drop from the chute into the socket.

62 denotes a pin projecting from the carrier and adapted to engage one of the arms 46 to stop the movement of the carrier at the exact instant the carrier is in position to receive a blank, and 63 denotes a pin projecting from the other side of the carrier which is adapted to engage the other arm 46 to stop the movement of the carrier when swinging from the position in Fig. 8 at the instant the blank is released and passes onto the tap.

The tap is provided with an angular shank and is retained in place by means of upper and lower pairs of jaws indicated respectively by 65 and 66. These jaws are pivoted upon the framework as at 67, are provided with half-sockets 68 which together form sockets to receive the tap and are thrown to the open position when released by a spring 69, the ends of which are connected to the shanks of the jaws. The jaws are closed to grip the tap by means of closing wheel 29 which is provided in opposite faces with recesses 70 which, terminate at their forward ends in abrupt shoulders and at their rear ends in inclines 71. The rear ends of the shanks of the jaws are provided with engaging screws 72 shown as provided with set nuts to lock them in position after adjustment. The ends of these screws are adjusted to bear firmly upon the opposite faces of the closing wheel, the action of which is to retain the shanks of the jaws distended and to cause the jaws to grip the tap firmly until recesses 70 pass into alinement with the engaging screws, when springs 69 will cause the screws to drop into the recesses and will draw the shanks together and open the jaws. An instant later, the engaging screws will ride up inclines 71 and the jaws will be caused to grip the tap again. It will be noted in Fig. 3 that the lower jaws are directly under the upper jaws and that the upper aws must be closed before the lower jaws can be opened, so that the tap is always gripped by one pair of jaws, as will be more fully explained.

After the nut has passed onto the tap it is rotated thereon by means of a carrier 73. This carrier is provided with an angular longitudinal opening through which the tap extends and which just receives the blanks and with a flange which rests upon a horizontal portion of the framework (see Fig. 17 in connection with Fig. 2). At the lower end of the carrier is a bevel gear wheel 74 which meshes with a bevel gear wheel 75 on the inner end of shaft 24 and causes rotation of the carrier. In order to start the blank upon the threads of the tap I provide a. tubular pusher 76 which swings loosely over the tap (see Fig. and acts to press the blank down on the threads of, the tap and start the threading or tapping operation, so that as the blank is rotated by the carrier it will pass over the threaded portion of the tap and the tapped nut will drop down upon the upper jaws. The pusher is pivoted at the outer end of an arm 77 which extends from a shaft 78 journaled in a bracket 79 extending from the framework. At the other end of shaft 7 8 is an arm 80 to which a link 81 is connected. The other end of this link is pivoted to arm 51 which itself receives motion from link 50 and actuates the carrier.

At the instant the swinging carrier is taking a blank from the hopper the pusher is forcing the last previous blank into engagement with the threads of the tap. While the swinging carrier is passing from the position shown in Figs. 2 and 7 toward the position shown in Fig. 8, the pusher will be passing from the position shown in full lines in Fig. 2 toward the position shown in dotted lines in said figure. The carrier and pusher keep out of each others way. As soon as the carrier is out of the way in swinging upward the pusher will be in position to start the blank on the tap. The tapping operation takes. place while the carrier is taking another blank. The exact timing of the machine is of course not an essential feature of the invention. The tapping operation might easily be made to commence before the carrier reaches its upward position, as in Figs. 2 and 7, or it might be made to continue an instant after the carrier has commenced to swing downward. Simultaneously with the dropping of the threaded nut from the threads of the tap, engaging screws 72 in the shanks of the upper jaws will drop into recesses 70 in the closing wheel and the corresponding spring 69 will draw the shanks together and open the jaws permitting the nut to drop through the upper jaws and rest upon the lower jaws. An instant later the engaging screw 72 of the upper jaws will ride up inclines 71 on the closing wheel and will close said upper jaws, causing them to again grip the tap firmly. An instant after the tap is again gripped by the upper jaws the engaging screw 72 of the lower jaws will drop into recesses 70 in the closing wheel and the lower jaws will be opened by the corresponding spring 69 and the threaded nut will drop through the lower jaws and off from the shank of the cap. An instant later the lower jaws will also grip the tap which is held firmly by both pairs of jaws during the entire tapping operation and is never released by either pair of jaws until it is firmly gripped by the other pair. In order to guard against the possibility of the tap shifting its position I preferably provide the shank of the tap with a notch 82 (see Fig. 16) and provide the half-socket in one of the jaws, in the present instance one of the upper jaws, With a lug 83 which engages said notch and centers and retains the tap.

The operation of the machine as a whole has been so fully explained as to hardly require further description. Briefly, the nut blanks, which have central holes punched therein, are thrown loosely into the hopper and are stirred about therein by the agitator which forces the lower layer of blanks up the inclined bottom and also up the curve of the concave wall, a portion of the blanks dropping into the chute and the others dropping backward on the top of the supply in the hopper. The swinging carrier takes the blanks singly from the lower end of the chute and transfers them onto the tap and into the rotary carrier, a slide on the swinging carrier retaining the blank in place therein until the carrier is in position to drop it upon the tap and then moving backward to permit the blank to drop out. As soon as the blank has been deposited on the tap the pusher engages the blank and starts it upon the threads of the tap. The tap remains stationary and the blank is rotated about it by the rotating carrier. As soon as the tapping operation is completed the tapped nut drops down upon the upper jaws which open and permit it to pass through and then close upon the tap again. An instant later the lower jaws open and permit the nut to pass through and off from the shank of the tap, the tap being firmly gripped at all times by one pair of jaws and during the tapping operation by both pairs of aws.

Having thus described my invention I claim:

1. A nut tapping machinecomprising a tap, upper and lower pairs of aws for holding the tap and provided with operating shanks, means acting on the shanks of each pair of jaws tending to bring them together to open the jaws, means for holding the shanks of both pairs of jaws normally separated to close the jaws, said holding means including means for successively releasing the shanks of both pairs of jaws, said release being timed so that the tap is always supported by at least one pair of jaws, and means for rotating the blanks.

2. A nut tapping machine comprising a tap, upper and lower pairs of jaws for holding the tap and provided with operating shanks, means acting on the shanks of each pair of jaws tending to brin said shanks together to open the jaws, an located between the shanks of both pairs of jaws to hold the latter normally closed, said cam being provided with means for releasing the shanks of both jaws, said release being timed so that the tap is always supported by at least one pair of jaws, means for rotating the blanks.

a single cam carrier, and means for actuating said arm 3. A nut tapping machine comprising a tap, a magazine, a swinging carrier provided with a slide for retaining the successive blanks as they are discharged from the magazine, means for withdrawing said slide to release each blank when the latter is placed on said tap, means for rotatingthe released blank, and a pusher for directly engaging said blank to force the latter over said tap.

4. An improvement in nut tapping machines comprising a non-rotary tap, a rotatable carrier having a longitudinal opening through which said tap extends and which just receives the blanks, a magazine, a swinging carrier provided with a slide for retaining the successive blanks as they are discharged from the magazine, means for withdrawing said slide tosuccessively release each blank when the latter is placed on said tap, and means for forcing the blank through the opening into said rotatable carrier when released by said swinging carrier.

5. An improvement in nut tapping machines comprising a non-rotary tap, a rotatable carrier having a longitudinal opening through which said tap extends and which just receives the blanks, a magazine, a swinging blank carrier provided with a slide for retaining the successive blanks as they are discharged from the magazine, a slide-operating arm supported by said blank as the carrier approaches either limit of its movement.

6. An improvement in nut tapping machines comprising a non-rotary tap, a rotatable carrier having a longitudinal opening through which said tap extends and which just receives the blanks, a magazine, a swinging blank-carrier provided with a slide for retaining the successive blanks as they are discharged from the magazine, a slideoperating arm supported by said blankcarrier, and spaced-apart fixed stops for engaging said arm.

7. An improvement in nut tapping machines comprising a non-rotary tap, a rotatable carrier having a longitudinal opening through which said tap extends and which just receives the blanks, a magazine, a swinging blank-carrier provided with a slide for retaining the successive blanks as they are discharged from the magazine, an arm having one end pivotally connected with said blank-carrier and the other end pivotally connected with said slide, and means for periodically oscillating said arm.

8. A nut tapping machine comprising a tap, a magazine provided with means for feeding blanks on edge, a swinging carrier for turning said blanks at right angles to position them over said tap, sald carrler being provided with a slide for retaining the blanks, means for automatically operating said slide, means for rotating the blank with respect to said tap, and means for starting the blank on the tap.

9. In a machine of the character de scribed, the combination with a stationary tap and means for rotating the blanks singly, of a swinging carrier by which blanks are placed on the tap singly and a slide on said carrier by which blanks are retained in place and means for moving said slide to release the blanks when in alinement with the tap.

10. A nut tapping machine comprising a. hopper having a chute and a swinging carrier having a socket in one face to receive a. single blank, means cooperating with said socket to retain the blank therein, a tap arranged to receive the blanks from the carrier, means for releasing the blank from said retaining means, and means for eflecting relative rotation of the blank and tap to thread the former.

11. In a machine of the character described, the combination with a tap and means for rotating the blanks, of a hopper having a chute, an arc-shaped swinging carrier having a socket adapted to receive a blank from the chute, a slide on the carrier which retains the blank in the socket and means for retracting the slide and permitting the blank to pass onto the tap.

12. In a machine of the character described, the combination with a tap and a hopper having a chute, of an arc-shaped swinging carrier intermediate the chute and the tap and provided with a socket to receive a blank, a slide to retain the blank in the socket, an arm pivoted to the carrier and pivotally connected to the slide and means engaged by the arm to advance or re tract the slide at either extreme of movement of the carrier.

13. In a machine of the character described, the combination with a tap and a hopper having a-chute, of an arc-shaped swinging carrier intermediate the chute and the tap and provided with a socket to re ceive a blank, a slide to retain the blank in the socket, an arm pivoted to the carrier and pivotally connected to the slide, means engaged by the arm to advance or retract the slide at either extreme of movement of the carrier and stops for the carrier when in position to receive a blank from the chute and place it upon the tap.

14. In a machine of the character described, the combination with a stationary tap and means for rotating a single blank, of means for placing the blanks singly on the tap, upper and lower pairs of jaws for holding the tap, springs for opening the pairs of jaws when released, inwardly projecting engaging screws in the shanks of the jaws and a closing wheel against which the ends of the screws bear to cause the jaws to grip the tap, said wheel being provided with recesses into which the screws drop to release the jaws, the screws then riding up the inclines to close the jaws again.

15. In a machine of the character de scribed, the combination with a stationary tap and means for rotating a single blank, of means for placing the blanks singly on the tap, upper and lower pairs of jaws having inwardly extending screws in their shanks, a closing wheel lying between the shanks of both pairs of jaws and provided on opposite sides with recesses having inclines at their rear ends and springs whereby the screws are drawn into the recesses to open the pairs of jaws successively, the screws then engaging theinclines and closing the first pair of jaws before the second pair is opened.

In testimony whereof I aflix my signature in presence of two witnesses.

FREDERICK C. HOFFMAN. Witnesses:

RoBT; P. LEWIS, LANCASTER P. CLARK. 

